I went through this a year ago with my 06 LTD. You have two economical options, both easy DIY for anyone with a little auto shop experience: Option 1, suitable if you never tow anything, is simply bypass the external trans cooler entirely. Option 2 (what I did) is throw away the OEM cooler and replace with e.g. Hayden, mounted in front of AC condenser. The Hayden cost me about $45, plus another $10 or so for hose. Even a "discount" Toyo dealer on the OEM cooler is going to be > $300. There is no magic here.